Magnetic cut-out plug



June 5, 1928. 1,672,729

C. PAPE MAGNETIC CUT-OUT PLUG Filed Nov. 5, 1925 Figi 52.5. 3/ 24 25 5 4/6 (5 z5 /525 27 30 11 28 Inventor: Carl Pape,

HLAttomeg.

Patented Jane 5, 192s. ,i

CARL PAPE, F BERLIN, GERMANY, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A

CORPORATION OF NEW YORK.

MAGNETIC CUT-OUT PLUG.

` 4Applimnm med November 5,

The present invention relates to automatic safety devices for protectingelectric circuits and apparatus from injury upon the occurrence ofexcess lflow of current. 6 -The general practice, especially in dwellinghouses, is to em loymfuse plugs' for the. ectric equipment thereof,

protection of'tl e but fuse plugs areobjectionable in that they aredestroyed upon a single operation or l0 blowing thereof and require tobe replaced by fresh ones.

, The object of my invention is the provi-A s1on of an improved cut-outplug, which shall be capable of an unlimited number of operations andwhich shall operate delinitely to open the circuit in which it is in-`stalled at the prescribed overload and without scattering of moltenmetal.'

One embodiment of the invention is shown in theaccompanying drawing inwhich Fig.

1 is a vertical axial section of the plug with 7 the parts in the on orclosed circuit relation; Fig. 2 is a transverse section taken' on line 22 of Fig. 1; Fig. 3 is a section similar to that of Fig. l, but with theparts in the Cif or open' circuit relation; Fig. 4 is a transversesection taken on line 4-4 of Fig. 3, and Fig. 5 is a transverse sectiontaken von line l5 5 of Fig. 3.

The base or body part of the (plug com,- prises yupper andv lowercup-shape members 1 and 2 of moulded insulation held together bylongitudinal screws 3. The lower member 2 hasl a bottom projection 4onwhich are mounted the usual center and screw shell contacts 5 and 6similar to the usual fuse plug contacts.

Within the cavity of the lower base member 2 and arranged concentricallythereof are a guide bush 7, a coil 8 of magnetic wire, and a magnetarmature 9 freely movable longitudinally through the center of the coil8. Secured within the lower base member 2 above the coil 8 is aninsulating disk 10'centrallyapertured to provide a guide passage for thearmature therethrough and having mounted on its upper surface twostationary switch contacts 11 and 12. One switch coniact is connected inwell known manner, as

5o by a lead wire tothe screw shell contact 6, while, the other switchcontact is connected 'to one end of the coil of magnet wire andtherethrough to the center contact 5.

The armature 9 carries above the disk 10 56 an insulating head 13 inwhich is .embeddedl v sided lug 16 at the end. The .armature-'isf `20yfixed therein which engages the sides of' 28 in the inner wall of theup 1925, Serial No. 67,138, and in Germany ,December 17, 1924.

the movable pole piece 14 of the switch and above the head. 13 is a hub15 with the sides cut away near the-end to form a parallel-` rotatablybiased in a clockwise direction by a clock spring 17 disposed in acentral cavity 18 formed in the lower side ofthe insulating disk 10,whereby the pole piece 14 normally tends to move away from the contacts11 and 12 and into the position indicated in Fig. 4 against the stops 19projecting inwardly4 from the sides of the upper base member 1.

The armature is held latched in the on or closed position -of the switchby a cross-bar notches 21 extending upwardly from the top of the cavity18 into the disk A10, and the `ine'ans for preing the armature 9longitudinally upward is a helical spring 22 located between its lowerend and the guide'block This 4spring is made suiliciently stiff toresist movement of the armature downward under the action 'of the magnetthereon,

while normal current is flowing, but yields upon the occurrence ofexcess current flow and thereby permits the cross-bar 20vto escape fromits retaining notches 21, wherelupon the biasing spring 17 causes it torotate upon its vaxis to carry the switch pole into off-position.

In order to reset the switch in the on or closed position, the up erbody part 2 has swiveled therein a thum piece 23 comprising.. a-langedinner part 24 and an outer thimbleshapedl part 25 rigidly attached tothe inner part, wlth a sprln 26 interposed therebe-4 tween and adapt tofrictionally restrain the rotary movement thereof. 'The flange 27 of theinner part is seated in a circular recess er body part 2, one-half ofwhich is made4 eeper than the' other, as indicated in Fi ..3 and 5, andthe flange 27 is provided wit a thickened uadrant 29 adapted to playfreely in the eepened portion of the recess 28, but limlted 100 to aquarter turn therein. The inner art 24 of the thumb-piece has acylindrica recess- 30 adapted to receive the upper end of the hub 15,and extending upwardly as an extension to the cylindrical recess 30 is a106 Y switch-so long as theexcess -ow of current v coll 1n said base,

engagmg -the notches thereo 16 pulled clear of the coupling mortise 3lin the thumbpiece 23 so' that turningof'the thumb piece may notoperateto reclose the continues through the magnet coil 8.

, While I have shown and described the best embodiment ofthe inventionknown to me, I donot desire to be restrictedthereto.

What IV claim as new and desire to secure by Letters Patent of theAUnited States, is

1. A magnetic switch plug comprising a base provided with side and endterminals, a magnet coil concentrically arranged in said base, a notchedinsulating disk enclosing said coil insaid base, switch contacts on saiddisk, Aa rotatably biased" armature extending throughsaid disk andhaving provisionsffor a movable switch member carried by said armature,and a thumb piece extending through said base and provided with meansfor engaging said movable switch member. v

2. .A magnetic switch plug comprising a.

base provided with side and end terminals, ,a

mao'net coil .concentricallyarranged in said C base,

a notched insulating disk enclosing 'said a'rotatably and-axially biasedarmature' eX- tending through said disk and having provisions forengaging the notches thereof in `unretracted position, a movable switchmem- 30 switch contacts on said disk,

ber fixed to sa'd armature, and a thumb piece mounted for rotarymovement in a fixed plane and provided with means for operativelyengaging said movable switch member only when in unretracted position.

In witness whereof, I have -hereunto set my hand this 12th day ofOctober, 1925.

CARL PAPE.

